Doing Some Baking in
Phoenix
Super-temps in desert operation force processing equipment to show its
mettle.
For the most part, being an asphalt and concrete
recycler in the Phoenix area is as good as it gets. Warm temperatures, low
humidity and an economy that seems impervious to downturn are all elements
for success. When those temperatures exceed 110° for extended periods of
time, however — as they regularly do in the summer months — key processing
equipment such as crushers and screens can be stopped (ironically speaking)
cold. For Mark’s Valley Grading & Excavating, a combination of wise
equipment purchases and a comprehensive maintenance effort has helped make
certain that doesn’t happen. The success of those efforts was proven out
this past summer when the firm operated without downtime during a 48-day
span of 110+° days.
Established some 22 years ago, Mark’s Valley Grading &
Excavation provides a broad range of services in and around the Phoenix
area. In fact, according to site foreman Steve Rhodes, the company’s name
really belies its capabilities.
“We do grading and excavation, but we also do a good
deal of residential and commercial demolition, removal of pads from housing
and large buildings, and more. That type of work obviously produces a
sizable volume of recovered concrete and asphalt, which prompted our owner,
Mark Haight, to establish a site at which we could stockpile and process
material from our own projects.”
That was about three years ago but Rhodes says the
effort has been so successful that today it is a full-fledged material
recovery facility called ‘Contractor’s Landfill’ where material is taken in
from area contractors and made into usable product.
Under most circumstances, the recycling site operated
by Mark’s Valley is similar to those found elsewhere. The firm takes in
concrete debris and asphalt from throughout the area, does a bit of
pre-processing when necessary, and feeds it to a CEC impact crusher/screen
plant to create product.
“The overwhelming majority of what we make is base
material for use in road work, general construction, pad work and so on,”
says Rhodes. “The CEC is set up with 1 1/4-inch screens for creating the AB
material. Then all the fines — we generally use dirt — are added to meet
the desired Maricopa Association of Governments (MAG) spec. The processing
itself is fairly typical of what you might find anywhere else in the
country. What sets us apart are the conditions in which we sometimes have
to keep running, and that’s where the reliability of the equipment comes
in.”
Rhodes cites a period this past summer in which
temperatures got as high as 122° during the day and on many occasions barely
dropped below 100° at night. Severe even by Phoenix standards, the
conditions lasted for better than a month and a half.
“It was an unbelievable stretch,” he says. “It’s hard
to believe that equipment can even run in that kind of heat, let alone do
something as tough as crushing and screening rock, but our system never let
us down. The units are equipped with high-volume radiators which kept
things under control, but we still had to constantly check the onboard
indicators to monitor water, oil, and hydraulic fluid temps. However, in a
situation like that, the biggest thing we can do to beat the heat is get as
much processing done in the early morning hours as we can. So it’s not
unusual for us to start getting things going at 4:00 a.m. and have almost a
full day’s processing in by the time most people are breaking for lunch.
But during those unbelievably tough stretches, there’s no denying the
heartiness of the equipment is what really gets us through.”
The primary system in place at Contractor’s Landfill
features a CEC Model 133 x152 Impact Crusher (Construction Equipment
Corporation, Tualatin, OR) feeding a 6 X 16 Screen-It® dual deck
screen plant, also from CEC.
“On average, we regularly crush 300 tons of concrete an
hour through the CEC plant,” says Rhodes. Rates for Ground Screened Asphalt
(GSA), because it is a softer material, will be a bit higher, pushing the
350-400 tph range. So with average conditions, we can easily do 2,000-2,500
tons of material a day.”
In addition to the main crushing/screening spread,
Mark’s has a CEC Track Screen-it plant with twin 5 X 12 screens through
which they make several different products; everything ranging from track
out rock, to 3” - 6” rip rap, to topsoil blends. They also recently added
another crusher that they are using to crush river rock prior to sending it
to the impact crusher to make their AB.
“The crushers and screens are our bread and butter
equipment,” says Rhodes. “Other than the support vehicles such as loaders
and trucks, the only other specialized equipment we have is a pair of
excavators with concrete pulverizer attachments on them which we use to
crush large concrete debris and free up any rebar that might be contained
within, before passing it along for crushing. Ultimately, it’s all about
getting it small and sized right.”
In severe conditions like those experienced this past
summer, efforts made in the design of the crushing and screening equipment
to minimize maintenance-related downtime really pay off. According to
Howard Glemming, CEC’s area sales representative, those efforts can start
with something as basic as designing the crusher’s blow bars for easy
top-load replacement, and go from there.
“While we maintain a nice inventory of replacement
parts, CEC has also worked hard to standardize replacement parts for the
customer’s convenience,” he says. “Hoses and connectors, for example, can
be purchased at any major auto parts supplier in town. So now, if a hose
breaks, the customer can simply call the store, tell them the length of the
hose and the size of fitting, and be back up in no time. Also, CEC has
done an excellent job of reducing screen cloth costs, again through the
design of the Screen-It unit itself. The angle of the screen deck is
relatively steep, reducing the likelihood that material will bounce very
high off the deck surface and cause excessive wear. These, and other
features have kept costs — and production interruptions — down.”
Over the years, both Mark’s Valley, the company and
Contractor’s Landfill, the location, have grown steadily in size. Today,
Mark’s works throughout a 75-mile radius and employs better than 120 people
company-wide. And the Landfill site has become a major player in supplying
base material to area contractors.
“People in this area — from Paradise Valley to Queen
Creek to Casa Grande to Florence — know that we will provide a good,
consistent product and are equally confident that, regardless of how hot it
gets, we will have product for them. That speaks volumes both for the
people we have at work for us and the equipment that performs day in and day
out.”
